Heterogeneous Polymer Dynamics Explored Using Static 1H NMR Spectra.

ABSTRACT: NMR spectroscopy continues to provide important molecular level details of dynamics in different polymer materials, ranging from rubbers to highly crosslinked composites. It has been argued that thermoset polymers containing dynamic and chemical heterogeneities can be fully cured at temperatures well below the final glass transition temperature (Tg). In this paper, we described the use of static solid-state 1H NMR spectroscopy to measure the activation of different chain dynamics as a function of temperature. Near Tg, increasing polymer segmental chain fluctuations lead to dynamic averaging of the local homonuclear proton-proton (1H-1H) dipolar couplings, as reflected in the reduction of the NMR line shape second moment (M2) when motions are faster than the magnitude of the dipolar couplin

SUBMITTER: Alam TM 

PROVIDER: S-EPMC7432559 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature